Cast cutter



Nov. 21, 1939. BUTKIEWICZ 2.180,457

CAST CUTTER Filed April 15, 1958 2 Sheets-Sheet l Inventor A iiorneys NOV. 21, 1939. U Z 2,180,457

CAST CUTTER Filed April 15, 1958 2 Sheets-Sheet 2 In ventor f g/ah zed/122 a; '62

A itorneys Patented Nov. 21, 1939 UNITED, 's-TATEs ATENT OFFICE CAST CUTTER Felix Butkiewicz, Omro, Wis. Application April 15, 1938, Serial No. 202,317 4' Claims. (01. 12s 317) The present invention relates to rotary shears designed primarily for use in cutting plaster of Paris casts and similar bandages and has for its primary object to provide a fixed cutting blade adapted to engage an edge portion of the cast and a rotary cutting blade cooperating with the fixed blade to perform thecutting action, said rotary cutting blade embodying teeth curved in a direction for engaging the cast and holding the same during the cutting action as well as operating to feed the gear inwardly into successive cutting position.

A further object is to provide a novel ratchet operating mechanism for the rotating cutting blade and operatively engaged with the rear edge of the teeth of the blade to produce the rotary movement thereof.

A still further object is to provide a device of this character of simple and practical construction, which is efiicient and reliable in performance, strong and durable, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which Figure l is a side elevational view of the gears shown in cutting position.

Figure 2 is a side elevational view of the stationary cutting blade detached from the gears.

Figure 3 is a top plan view,

Figures 4, 5 and 6 are sectional views taken respectively on the lines 3-l, 5-5 and 6-6 of Figure 1, and V Figure '7 is a perspective view of the ratcheting pin.

Referring now to the drawings in detail, wherein for the purpose of illustration I have disclosed a preferred embodiment of the'invention, the numeral 5 designates a stationary cutting blade having a handle 6 projecting from one edge thereof and secured in overlapping relation with respect to one face of the blade by rivets T. An opening 8 extends through the blade 5 as well as through the lower end of the handle 6 for receiving a pivot pin 9 upon which one end of a manipulating handle 19 is pivotally carried. One edge of the opening 8 is formed with a keyway H and a similar key-way is formed in one end of the pin 9, as at l2 for receiving a key #3 held in position by a nut i l threaded on one end of the pin whereby to secure the pin against being of cylindrical form and rotation to the blade 5. The opposite end of the pin is formed with a head [5 which engages the outer surface of the handle it] to secure the same in position.

One edge of the blade 5 is formed with an inwardly extending hook 16, the inner edge'of the hook being curved and beveled as at ll to provide a knife edge.

A rotary cutting blade l8'is freely mounted on the pin 9, said blade being interposed between the blade 5 and the pivoted end of the handle W as will be apparent from'an inspection of Figures 3 and 4 of the drawings. The blade i8 is provided on its periphery with a plurality of arcuate teeth IS, the inner edgeof which are beveled as at 2!! to form a knife edge for cutting engagement with respect to the knife tionary blade. 1

The pivoted handle l-B, adjacent its pivoted end, is provided witha threaded opening 28 for threadedly receiving the inner end of a cylindrical pawl housing 22, the outer end of which is closed and provided with acentral opening 23. A pawl 24 is slidably mounted in the housing 22, the pawl provided at one end with a reduced threaded extension 25 which projects outwardly through the opening 23 for threaded engagement by a cap 26. The cap is secured to the housing 22 against the rotary movement by means of a pin 2! projecting radially from the housing and inserted in a notch 28 formed on the wall of the cap,'as clearly shown in Figure 3 of the drawings.

The inner end of the pawl 24 is provided with a head 29against which a coil spring 30 abuts,. said springbeing mounted in the housing 22 for projecting the pawl inwardly through the open end of the housing into position between the teeth l9 of the rotary blade l8. By reason of the threaded engagement of the pawl withthe cap 26, the pawl is secured against rotary movement and the free end of the pawl, at one side thereof, is beveled as shown at 3i, while the opposite side of the free endof the pawl is provided with a notch 32 to define a shoulder for engaging the rear edge of the teeth l9 whereby to move the rotary cutter counterclockwise upon the manipulation of the handle ill. of the pawl enables the pawl to ride past the teeth during the opening movement of the handle in a manner as will be apparent.

In the operation of the device, the hook end l6 of the stationary blade 5 is engaged under theplaster of Paris cast shown by the dotted lines at 33 which may be surrounding the arm 34 of edge I! of the sta- The beveled edge- 3! a person so that the edge of the cast is engaged by the knife edge I! of the stationary blade and upon a closing movement of the handle Ill the rotary cutter l8 will be turned counter-clockwise, causing the pointed ends of the teeth I9 to bite into the cast and force the same against the knife edge I! to produce a cutting action. As the rotation of the cutter l8 continues the teeth l9, by reason of their engagement with the cast, will pull the cutter along the cast in a direction toward the left, as seen in Figure 1.

It will be observed the blade has its marginal edge projecting out beyond the ends of the teeth l9 to provide protection against injury to the patient, operator or other instruments and materials.

The pawl head 29 may be retracted out of engagement between the teeth of. the rotary cutter to permit reverse movement of the cutter by pulling the cap 26 outwardly and giving the cap a partial turn to rest the edge thereof on the pin 21.

It is believed the details of construction and manner of operation of. the device will be readily understood from the foregoing without further detailed explanation.

Having thus described the invention, what I claim is- 1. A cast cutter comprising a stationary blade having a rearwardly extending work engaging hook, a rotary blade mounted in cutting cooperation with said stationary blade, said blades being adapted for movement in a rearward direction during cutting operation, said rotary blade embodying a plurality of cutting teeth and ratcheting means engageable with the teeth for operating the blade, said teeth being arcuately formed and embodying work penetrating prongs and adapted to engage and force the work into cutting engagement with said stationary blade.

2. A cast cutter comprising a stationary blade,

a rotary blade mounted in cutting cooperation with said stationary blade, said rotary blade embodying a plurality of cutting teeth and ratcheting means engageable with the teeth for operating the blade, said teeth being arcuately formed and embodying work penetrating prongs and adapted to engage and force the work into cutting engagement with said stationary blade, said ratcheting means embodying a spring projected pawl engageable with the rear edge of said teeth and a manipulating handle for said pawl.

3. A cast cutter comprising a stationary blade having a knife edge terminating in a rearwardly extending hook, a handle projecting rearwardly from the blade, a pivot pin carried by the blade, a movable handle pivoted at one end to said pin, a rotary blade freely mounted on said pin, said rotary blade embodying a plurality of. arcuate teeth cooperating with said stationary blade and ratchet means carried by said movable blade and engageable with the teeth for actuating said rotary blade.

4. A cast cutter comprising a stationary blade having a hooklike knife edge, a handle projecting from one edge of the blade, a pivot pin carried by the blade, a movable handle pivoted at one end to said pin, a rotary blade freely mounted on said pin, said rotary blade embodying a plurality of arcuate teeth cooperating with said stationary blade and ratchet means carried by said movable blade and engageable with the teeth for actuating said rotary blade, said ratcheting means embodying a spring projected pawl carried by the movable handle, one end of the pawl being positioned between the teeth for successively engaging the same, means for securing the pawl against rotation and a beveled edge on the end of the pawl to facilitate riding of the pawl past the teeth during a reverse movement of the movable handle.

FELIX BUTKIEWICZ. 

